This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A226892 #12 Sep 05 2021 22:03:08 %S A226892 0,29,69,153,373,917,2321,5933,15317,39737,103461,269925,705169, %T A226892 1843709,4822949,12620249,33029909,86456693,226319505,592468365, %U A226892 1551031477,4060538489,10630442309,27830559173,72860864273,190751433437,499392464901,1307424389913 %N A226892 Number of squares of size n^2 in all tilings of an (n+2) X (n+2) square using integer-sided square tiles. %H A226892 Alois P. Heinz, <a href="/A226892/b226892.txt">Table of n, a(n) for n = 0..1000</a> %F A226892 G.f.: (17*x^5 - 29*x^4 - 73*x^3 + 65*x^2 + 47*x - 29)*x / (-x^6 + 2*x^5 + 4*x^4 - 6*x^3 - 2*x^2 + 4*x - 1). %e A226892 a(1) = 29: %e A226892 ._._._. ._._._. ._._._. ._._._. ._._._. ._._._. %e A226892 | | | |_| |_|_|_| |_| | |_|_|_| |_|_|_| %e A226892 | | |___|_| | |_| |_|___| |_| | |_|_|_| %e A226892 |_____| |_|_|_| |___|_| |_|_|_| |_|___| |_|_|_|. %Y A226892 A diagonal of A226936. %K A226892 nonn %O A226892 0,2 %A A226892 _Alois P. Heinz_, Jun 22 2013